Conventionally, if a personal computer or server is shielded by use of ground (GND) potential, it is generally known to use a method for sufficiently stably connecting a metal casing to a ground terminal on a printed-wiring board by use of screws or the like and making the metal casing itself function as a shield based on the ground potential.
However, in the case of a small and thin mold type semiconductor memory device, a substrate including a chip is entirely sealed with resin. Therefore, even if the metal shield is provided outside the mold, it is impossible to directly connect the metal shield to the ground terminal on the substrate of the semiconductor memory device.